Hub and bearing assembly with integrated rotation sensor including a tone ring and annular transducer

ABSTRACT

A bearing assembly incorporating a speed and/or temperature sensor particularly adapted for motor vehicle wheel applications. The sensor incorporates a magnetized tone ring defining a radial or cylindrical face which interacts with an annular transducer. The transducer has a plurality of teeth facing the magnetized tone ring with separate first and second rows of teeth extending from the transducer frame. The first set of teeth engage one area of the tone ring defining one magnetic pole whereas the second series of teeth interact with regions of the tone ring defining the opposite magnetic pole. Relative rotation between the transducer and tone ring induces an alternating magnetic field through the transducer case which induces an alternating voltage in the winding coil. The transducer is efficiently packaged within the enclosed cavity of a bearing assembly. This invention further contemplates a means to allow transducer temperature to be evaluated by monitoring the DC resistance of the transducer winding.



